@Romain thanks for all answers...
On Mon, Sep 1, 2014 at 1:18 PM, Romain Manni-Bucau <[email protected]> wrote: > transactions are mainly a thread local things so it is safe and has no > link with concurrency. > > > Romain Manni-Bucau > Twitter: @rmannibucau > Blog: http://rmannibucau.wordpress.com/ > LinkedIn: http://fr.linkedin.com/in/rmannibucau > Github: https://github.com/rmannibucau > > > 2014-09-01 12:15 GMT+02:00 Lars-Fredrik Smedberg <[email protected]>: > > @Romain > > > > Thanks for the answers... in question 4 I meant that if I annotate a bean > > with @TransactionAttribute will it still work as expected regardless of > if > > the bean instance is accessed with multiple threads at the same time or > > not (in the case of singleton read lock or singleton bean concurrency > > management )? > > On 1 Sep 2014 11:42, "Romain Manni-Bucau" <[email protected]> wrote: > > > >> Hi > >> > >> 1. true > >> 2. @ConcurrencyManagement(BEAN -> lock free, @Lock(READ) > >> reentrantLock.readLock().lock/unlock is called (performance wise > >> difference is not that important in general) > >> 3. it should. comparison is fair > >> 4. @TransactionAttribute defines the transactional context you want, > >> required will create or inherit running tx, required_new will always > >> creates a new one. CDI beans are "support" (ie I don't care) > >> > >> > >> > >> Romain Manni-Bucau > >> Twitter: @rmannibucau > >> Blog: http://rmannibucau.wordpress.com/ > >> LinkedIn: http://fr.linkedin.com/in/rmannibucau > >> Github: https://github.com/rmannibucau > >> > >> > >> 2014-09-01 10:32 GMT+02:00 Lars-Fredrik Smedberg <[email protected]>: > >> > Hi > >> > > >> > I have some questions on EJBs and concurrency, I hope someone can shed > >> some > >> > light on the following questions: > >> > > >> > 1. I have understood that the annotations @ConcurrencyManagement and > >> @Lock > >> > only are applicable to Singelton EJBs and that the default values are > >> > container managed concurrency and WRITE lock, correct? > >> > 2. What is the difference between annotating with > >> > @ConcurrencyManagement(BEAN) vs using container managed concurrency > and > >> > annotating @Lock(READ) ? Is there better performance wise to use BEAN > >> > managed concurrency if thread safety is no issue? > >> > 3. Will an EJB annotate @ConcurrencyManagement(BEAN) simply ignore any > >> > @Lock annotations? Is this the EJB equivalent to an @ApplicationScoped > >> CDI > >> > bean when it comes to concurrency? > >> > 4. Is this a totally separate function from using tx and annotation > >> > @TransactionAttribute ? I mean in the case of concurrent access to > >> business > >> > method in a bean that e.g. has @TransactionAttribute(REQUIRED) I will > >> start > >> > multiple transactions? > >> > > >> > Thanks > >> > > >> > Regards > >> > Lars-Fredrik > >> > > >> > -- > >> > Med vänlig hälsning / Best regards > >> > > >> > Lars-Fredrik Smedberg > >> > > >> > STATEMENT OF CONFIDENTIALITY: > >> > The information contained in this electronic message and any > >> > attachments to this message are intended for the exclusive use of the > >> > address(es) and may contain confidential or privileged information. If > >> > you are not the intended recipient, please notify Lars-Fredrik > Smedberg > >> > immediately at [email protected], and destroy all copies of this > >> > message and any attachments. > >> > -- Med vänlig hälsning / Best regards Lars-Fredrik Smedberg STATEMENT OF CONFIDENTIALITY: The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the address(es) and may contain confidential or privileged information. If you are not the intended recipient, please notify Lars-Fredrik Smedberg immediately at [email protected], and destroy all copies of this message and any attachments.
